Department of Fisheries and Oceans, Freshwater Institute, 501 University Crescent, Winnipeg, MT, Canada, R3T 2N6
Mass transfer efficiency between harp seal (Phoca groenlandica) mothers and their pups during lactation
Article first published online: 23 MAR 2009
Journal of Zoology
Volume 223, Issue 2, pages 213–221, February 1991
How to Cite
Kovacs, K. M., Lavigne, D. M. and Innes, S. (1991), Mass transfer efficiency between harp seal (Phoca groenlandica) mothers and their pups during lactation. Journal of Zoology, 223: 213–221. doi: 10.1111/j.1469-7998.1991.tb04761.x
- Issue published online: 23 MAR 2009
- Article first published online: 23 MAR 2009
- Accepted 16 January 1990
We investigated the efficiency of mass transfer in lactating harp seals through serial measurements on individual mother-pup pairs during the whelping seasons of 1988 and 1989. We also compared the influence of longitudinal versus cross-sectional sampling on estimates of the efficiency of mass transfer. Among longitudinally sampled pairs, pups grew at an average rate of 2·3 ± 0·5 (mean ± S.D.) kg/d (N = 20). The concomitant mass loss by females averaged 3·1 ± 0·8 kg/d (N = 19). The mean efficiency of mass transfer was 77·0 ± 13·6% (N= 19 pairs).
Estimates of pup growth and female mass loss from regressions of cross-sectional data were 2·0 kg/d and 3·1 kg/d, respectively. These values produce an estimate of 65% for the efficiency of mass transfer.
Consistent with the high efficiency of mass transfer, harp seal females contribute less of their total body mass to nursing (c. 28%) than most other phocids examined. The resulting energy savings may be important for females of an ice-breeding species, which migrate a long distance shortly after weaning their pups